[postgis-users] srid for epsg 26915

[David William Bitner]

The stock SRID in PostGIS for items from the EPSG database is always going
to be the same as the EPSG code. The PostGIS insert statement is for adding
spatial references to your PostGIS install.

David

On Wed, Sep 22, 2010 at 12:36 PM, David Fawcett <david.fawcett at gmail.com>wrote:

> OK, that makes sense.
>
> So, it works well when installing additional SRS' , you won't mess up
> your stock spatial_ref_sys.
>
> The use case that I was going after was where a co-worker wanted to
> know what srid to use when importing data from a shapefile.  I was
> attempting to use spatialreference.org as a reference to confirm what
> the standard SRID for this SRS in PostGIS was.  I guess that this
> conflict comes up for SRS' that are part of the stock install.
>
> Maybe there is a need for another line on the spatialreference.org
> page for 'PostGIS SRID' ?
>
> Of course,  if one already has rights to add data to the db, you can
> just run a simple (if you know the EPSG code):
>
> SELECT *
>   FROM public.spatial_ref_sys
> WHERE auth_name = 'EPSG'
>      AND auth_srid = 26915;
>
> David.
>
> On Wed, Sep 22, 2010 at 12:19 PM, David William Bitner
> <bitner at gyttja.org> wrote:
> > David,
> > spatialreference.org uses a local SRID with a prepended '9' while
> > maintaining an auth_srid to match EPSG so as not to step on the toes of
> the
> > SRIDs that are already in the spatial_ref_sys table. While a bit ugly,
> this
> > is the intended behavior. It uses the '9' because there are no EPSG codes
> > that begin with a 9 so it is a clear namespace to not overwrite an EPSG
> code
> > regardless of what local SRID identifier is given at
> spatialreference.org.
> > Clear as mud?
> > David
> >
> > On Wed, Sep 22, 2010 at 11:41 AM, David Fawcett <david.fawcett at gmail.com
> >
> > wrote:
> >>
> >> A minor issue here, but I am looking for some clarification.
> >>
> >> I am seeking the correct PostGIS srid for UTM Z15N NAD83.
> >>
> >> If I query spatialreference.org,
> >> (http://spatialreference.org/ref/epsg/26915/postgis/)  I get:
> >>
> >> INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text,
> >> srtext) values ( 926915, 'epsg', 26915, '+proj=utm +zone=15
> >> +ellps=GRS80 +datum=NAD83 +units=m +no_defs ', 'PROJCS["NAD83 / UTM
> >> zone 15N",GEOGCS["NAD83",DATUM["North_American_Datum_1983",SPHEROID["GRS
> >>
> >>
> 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6269"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4269"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-93],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],AUTHORITY["EPSG","26915"],AXIS["Easting",EAST],AXIS["Northing",NORTH]]');
> >>
> >>
> >> From a fairly recent of PostGIS,
> >>
> >> SELECT srid, auth_name, auth_srid
> >> FROM public.spatial_ref_sys
> >> WHERE auth_srid = 26915
> >>
> >>
> >> I get:  26915 | EPSG | 26915
> >>
> >>
> >> I am assuming that the definition at spatial ref.org is wrong?
> >>
> >> David.
> >> _______________________________________________
> >> postgis-users mailing list
> >> postgis-users at postgis.refractions.net
> >> http://postgis.refractions.net/mailman/listinfo/postgis-users
> >
> >
> >
> > --
> > ************************************
> > David William Bitner
> >
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> >
> >
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-- 
************************************
David William Bitner
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